This invention relates to a method for making a rolling electrode for use in an electrostatic device.
An electrostatic device is described in my U.S. Pat. No. 3,989,357, issued Nov. 2, 1976, wherein an electrically conducting sheet in the form of a spiral roll may be caused to unroll and become coadunate with an adjacent fixed electrode. The sheet may be composed of a plastic material on which there has been deposited one or more metal films. The roll is formed by winding the sheet about a mandrel, heating the wound sheet and removing the mandrel causing the sheet to take a set in the form of the mandrel.
Such a device may be used as an electrically controlled venetian blind or as a display device. For such use, the ratio of the amount of window area blocked by the rolled electrode to the amount of window are a blocked when the electrode is unrolled should be made as small as possible. A tight small roll of many turns is required to achieve a high window-blind efficiency, or to achieve a near unity ratio of active area to total display device area.
It is therefore an object of the present invention to provide a method for making a rolling electrode having a small rolled diameter compared with the extended length of the electrode.